Technical Field
[0001] The present invention relates to a drive apparatus for reducing speed of rotation
force of a hydraulic or electric motor serving as a drive source with an oil-filled
speed reducer unit, and transmitting the reduced rotation force to a driven portion
such as an upper slewing body, in a construction machine such as a hydraulic shovel.
Background Art
[0002] Taking a slewing drive apparatus for a shovel as an example, background art will
be described.
[0003] A shovel includes a crawler-type lower propelling body, an upper slewing body rotatably
mounted, around a shaft vertical to the ground, on the lower propelling body, and
a work attachment mounted on this upper slewing body.
[0004] The shovel further includes a slewing drive apparatus rotating the upper slewing
body. This slewing drive apparatus includes a hydraulic or electric motor serving
as a drive source, and a speed reducer unit reducing speed of rotation force of this
motor with a gear speed reduction mechanism and transmitting the reduced rotation
force to the upper slewing body, that is, the driven portion.
[0005] The motor has a motor shaft, and the speed reducer unit has a speed reducer output
shaft connected to the motor shaft. The motor and the speed reducer unit are provided
in a row in an axial direction of the slewing drive apparatus (hereinafter referred
to as an apparatus-axis direction) such that both center axes (the motor shaft and
the speed reducer output shaft) are located along the same line. Additionally, the
motor and the speed reducer unit are mounted to an upper frame in such a vertical
arrangement that the motor is located at a top.
[0006] The speed reducer unit is at least a single-stage planetary gear mechanism including
a sun gear, a planetary gear, and a ring gear, for example. Output of this speed reducer
unit is transmitted to the upper slewing body through a pinion provided on the speed
reducer output shaft, and a slewing gear provided on a lower frame of the lower propelling
body.
[0007] Lubricating oil for lubricating a gear mechanism such as the planetary gear mechanism
is injected in the speed reducer unit. A temperature of this lubricating oil increases
by heat generated by the slewing drive apparatus (speed reducer unit). Therefore,
the slewing drive apparatus is provided with a cooling means for cooling the lubricating
oil.
[0008] For example, Patent Document 1 describes a technique of providing a coolant path
in a casing of a speed reducer unit as the cooling means, and cooling lubricating
oil from an outer periphery by flowing a cooling medium such as water and oil in this
coolant path.
[0009] However, according to the technique described in Patent Document 1, there are the
following problems.
[0010] (I) A jacket structure, in which the coolant path is provided so as to have the size
in a range of a thickness of a peripheral wall of the casing, is employed. Therefore,
the thickness of the peripheral walls of the casing is required to increase, and a
diameter of the casing increases.
[0011] Accordingly, a maximum diameter of the drive apparatus increases, and a space occupied
by the drive apparatus in this diameter direction increases. Therefore, particularly
under a situation in which many apparatuses are densely placed in a small space like
the slewing drive apparatus for the shovel, the layout of the apparatuses becomes
difficult.
[0012] (II) In a case of the slewing drive apparatus, a shaft support portion provided on
a lower end of the speed reducer unit is bolted on the upper frame from above. Here,
according to the technique described in Patent Document 1, the casing of the speed
reducer unit increases in diameter by providing the coolant path. Therefore, a tightening
tool such as a wrench is difficult to enter due to interference of this casing, and
tightening or loosening work of a bolt for mounting the shaft support portion becomes
troublesome.
[0013] (III) The lubricating oil inside the casing is cooled only from an outer periphery
side of the casing. That is, only one surface (inner surface) of the coolant path
(casing) contributes to cooling. Therefore, a cooling effect is weak.
[0014] (IV) The coolant path is formed so as to have the size in the thickness range of
the casing. Therefore, as described in Patent Document 1, it is necessary to employ
a particular molding method such as molding using a core for the coolant path. Thus,
the manufacturing cost of the casing increases.
[0015] Patent Document 1: Japanese Patent Publication No.
4504899
Summary of the Invention
[0016] An object of the present invention is to provide a drive apparatus in which a cooling
effect of lubricating oil is enhanced and a manufacturing cost can be reduced while
the size is small in a diameter direction, and a construction machine provided with
the same.
[0017] In order to solve the problems, the present invention provides a drive apparatus
for a construction machine that includes a hydraulic or electric motor having a motor
shaft and serving as a drive source, a speed reducer unit having a speed reducer output
shaft for receiving rotation force from the motor shaft and transmitting this rotation
force to a driven portion, and a casing having lubricating oil injected therein, and
transmitting the rotation force of the motor to the driven portion while reducing
speed of the rotation force, and a cooler formed with a coolant path through which
liquid or gas for cooling the lubricating oil passes as a cooling medium, wherein
the motor and the speed reducer unit are provided in a row in an apparatus-axis direction
such that the motor shaft and the speed reducer output shaft are arranged along a
same line, and the cooler is provided in a row with the speed reducer unit in the
apparatus-axis direction in a state where at least a part of the cooler is immersed
in the lubricating oil, so as to enable heat exchange with the lubricating oil.
[0018] Furthermore, the present invention provides a construction machine including the
drive apparatus, and a driven portion which is driven by receiving force transmitted
through the speed reducer unit.
[0019] According to the present invention, the cooling effect of the lubricating oil is
enhanced and the manufacturing cost can be reduced while the size is small in the
diameter direction.
Brief Description of the Drawings
[0020]
[Fig. 1] Fig. 1 is a partial cross-sectional side view showing a first embodiment
of the present invention.
[Fig. 2] Fig. 2 is an enlarged perspective view showing a cooler shown in Fig. 1.
[Fig. 3] Fig. 3 is a sectional view taken along a line III-III in Fig. 1.
[Fig. 4] Fig. 4 is a partial cross-sectional side view showing a state where the cooler
is detached in the first embodiment.
[Fig. 5] Fig. 5 is a partial cross-sectional side view showing a second embodiment
of the present invention.
[Fig. 6] Fig. 6 is a partial cross-sectional side view showing a third embodiment
of the present invention.
[Fig. 7] Fig. 7 is an enlarged perspective view showing a cooler shown in Fig. 6.
[Fig. 8] Fig. 8 is a partial cross-sectional side view showing a fourth embodiment
of the present invention.
[Fig. 9] Fig. 9 is an enlarged perspective view showing a cooler shown in Fig. 8.
Best Mode for Carrying Out the Invention
[0021] With reference to the attached drawings, embodiments of the present invention will
be hereinafter described. The following embodiments each are an embodied example of
the present invention, and do not restrict the technical scope of the present invention.
[0022] An application item of each of the following embodiments is a slewing drive apparatus
for a shovel.
[0023] However, the present invention is also applicable to other drive apparatuses in which
a motor and a speed reducer unit are arranged in a row in an apparatus-axis direction
such that a motor shaft of the motor and a speed reducer output shaft of the speed
reducer unit are arranged along the same line, and lubricating oil is injected into
a casing of the speed reducer unit. Specifically, the present invention is applicable,
for example, to a propelling drive apparatus of a lower propelling body or a drive
apparatus of a winch. Furthermore, the present invention is also applicable to construction
machines other than the shovel.
[0024] In the following description, a vertically-mounted drive apparatus in which the motor
and the speed reducer unit are vertically located is taken as an example. However,
the present invention is also applicable to a horizontally-mounted drive apparatus
in which the motor and the speed reducer unit are located horizontally.
First Embodiment (see Fig. 1 to Fig. 4)
[0025] A slewing drive apparatus shown in Fig. 1 includes a hydraulic or electric motor
(generally, hydraulic motor) 1 serving as a drive source, a speed reducer unit 2 reducing
speed of rotation force of this motor 1 and transmitting the rotation force to an
upper slewing body as a driven portion, and a cooler 15 provided between the motor
1 and the speed reducer unit 2.
[0026] The motor 1 includes a motor housing 3, and a motor shaft 5 protruding from the motor
housing 3. The motor housing 3 includes a cylindrical housing body 3b, and a flange
3a protruding from a lower end of the housing body 3b to an outer periphery.
[0027] The speed reducer unit 2 includes at least single-stage planetary gear mechanisms
(two-stage planetary gear mechanisms in Fig. 1, and hereinafter described as a case
of the two-stage planetary gear mechanisms) 12 and 13, a casing 4, in which the respective
planetary gear mechanisms 12 and 13 are housed, and into which lubricating oil O is
injected, a speed reducer output shaft 6 connected to the respective planetary gear
mechanisms 12 and 13 and protruding from the casing 4, and a shaft support portion
8 rotatably supporting the speed reducer output shaft 6.
[0028] The aforementioned motor 1 and speed reducer unit 2 are arranged in a row in an apparatus-axis
direction (vertical direction) such that the motor shaft 5 and the speed reducer output
shaft 6 are arranged along the same center line Ce. Specifically, the motor 1 and
the speed reducer unit 2 are mounted to a construction machine in such a vertically
arranged state that the motor 1 is located at a top and the motor 1 and the speed
reducer unit 2 are provided in a row in the apparatus-axis direction. The flange 3a
provided on a lower end of the motor housing 3, and an upper end of the casing 4 are
detachably connected to each other with a plurality of connecting bolts 7.
[0029] The shaft support portion 8 is provided on a lower end of the speed reducer unit
2 (below the casing 4), and has therein a bearing rotatably supporting the speed reducer
output shaft 6. This shaft support portion 8 is provided with a mounting flange 9
protruding from a lower portion thereof to an outer periphery. The mounting flange
9 can be mounted to an upper frame 10 of the upper slewing body with a plurality of
mounting bolts 11.
[0030] The casing 4 houses the two-stage planetary gear mechanisms 12 and 13 arranged coaxially.
Furthermore, the lubricating oil O is injected into the casing 4 over the substantially
whole length of the casing 4. More specifically, the lubricating oil O is injected
into a range from a bottom surface of the casing 4 (boundary portion between the shaft
support portion 8 and the casing 4) to the flange 3a of the aforementioned motor 1.
[0031] The respective planetary gear mechanisms 12 and 13 reduce the speed of the rotation
force of the motor 1 and transmit the rotation force to the upper frame 10 (upper
slewing body) as the driven portion. Specifically, the respective planetary gears
12 and 13 include sun gears S1 and S2, carriers (also called spiders) C1 and C2, pluralities
of planetary gears P1 and P2 provided around the sun gears S1 and S2 through the carriers
C1 and C2, and a ring gear R provided on an inner periphery of the casing 4. Then,
the respective planetary gear mechanisms 12 and 13 make the planetary gears P1 and
P2 revolve while making the planetary gears P1 and P2 rotate on their own axes, thereby
reducing the speed of the rotation of the motor 1. The rotation force, which is reduced
in speed, of the motor 1 is transmitted to the speed reducer output shaft 6, and transmitted
to the upper frame 10 through a pinion 14 provided on a lower end of the speed reducer
output shaft 6 and a slewing gear (ring gear: not shown) meshing with this pinion
14.
[0032] In this slewing drive apparatus, the cooler 15 for cooling the lubricating oil O
in the casing 4 is provided between the motor 1 and the speed reducer unit 2.
[0033] The cooler 15 is a flattened circular box body having therein a coolant path 16,
through which liquid or an airframe passes as a cooling medium, as shown in Figs.
1 to 3. Furthermore, the cooler 15 is formed with a center hole (communication hole)
17 through which the motor shaft 5 can pass. The center hole 17 communicates between
spaces on both side of the apparatus-axis direction of the cooler 15 so as to allow
the lubricating oil O to circulate in a central portion of the cooler 15. Furthermore,
an outer peripheral wall (ring member 19 described later) of the cooler 15 is formed
with a plurality of bolt through holes (connecting portions) 22 along the vertical
direction in a range of a thickness thereof. The respective bolt through holes 22
allow the connecting bolts 7 to be inserted therethrough. Therefore, the cooler 15
is detachably attached to the motor 1 (flange 3a) and the speed reducer unit 2 (casing
4) with the connecting bolts 7 in a state where the motor shaft 5 passes through the
center hole 17.
[0034] Here, the center hole 17 is formed so as to have a diameter larger than that of the
motor shaft 5. Therefore, a clearance gap between an inner surface of the center hole
17 and the motor shaft 5 functions as a communication path 18 through which the lubricating
oil O circulates in spaces on both upper and lower sides of the cooler 15.
[0035] Furthermore, the ring member 19 configuring the outer peripheral wall of the cooler
15 is formed with an inlet 20 and an outlet 21 communicating between the inside and
the outside of the ring member 19. The inlet 20 and the outlet 21 are provided in
symmetric positions at 180° about the center line Ce.
[0036] The inlet 20 is connected to a coolant supply pipe (outside the drawing). Similarly,
the outlet 21 is connected to a coolant discharge pipe (outside the drawing). The
cooling medium (water or oil) is supplied to the coolant path 16 through the inlet
20. On the other hand, the cooling medium after heat exchange is discharged from the
coolant path 16 through the outlet 21.
[0037] The cooler 15 is mounted between the motor 1 and the speed reducer unit 2 in a state
of being partially immersed in the lubricating oil O. Specifically, the cooler 15
is mounted to the motor 1 and the speed reducer unit 2 in a state where an outer peripheral
surface of the ring member 19 is flush with an outer peripheral surface of the casing
4. In this mounting state, both of an upper surface and a lower surface of the cooler
15 are in contact with the lubricating oil O. Therefore, the lubricating oil O in
the casing 4 is cooled by the cooling medium supplied to the cooler 15.
[0038] According to this configuration, the following function effects can be obtained as
compared with a conventional jacket structure in which a coolant path is provided
on a peripheral wall of a casing.
[0039] (i) With respect to a cooling effect, the cooler 15 is partially immersed in the
lubricating oil O, so that heat exchange with the lubricating oil O can be performed
on the both side surfaces in the apparatus-axis direction of the cooler 15. Therefore,
a basically high cooling effect can be obtained.
[0040] Furthermore, the cooler 15 is provided with the communication path 18 for communicating
between the spaces on the both sides in the vertical direction of the cooler 15. Therefore,
it is possible to spread the lubricating oil O between the spaces on the both sides
in the vertical direction of the cooler 15. Thus, lubrication of the speed reducer
unit 2 can be inhibited from being blocked, and the cooling effect by the cooler 15
can be further enhanced.
[0041] (ii) With respect to the apparatus size, the cooler 15 is provided in a row in the
apparatus-axis direction between the motor 1 and the speed reducer unit 2. Thus, the
cooler 15 can be inhibited from protruding to a side of the outer periphery with respect
to the speed reducer unit 2, and a maximum diameter of the drive apparatus can be
reduced.
[0042] Accordingly, a space occupied by the apparatus as viewed from an axial direction
(above) can be reduced. Particularly, in a situation where there is not an enough
space in the diameter direction while there is an enough constant space in the vertical
direction as in a case where the slewing drive apparatus is provided in the shovel,
the degree of freedom of layout of apparatuses is improved.
[0043] Furthermore, the cooler 15 does not protrude from the speed reducer unit 2 to the
outer periphery, and therefore there is no risk of disrupting tightening operation
and loosening operation of the respective mounting bolts 11 with respect to the upper
frame 10.
[0044] Moreover, the planetary gear mechanisms 12 and 13 that are compact in an axial direction
are used as the speed reduction mechanisms of the speed reducer unit 2. Therefore,
even when the cooler 15 is provided on an intermediate portion in the apparatus-axis
direction, the whole apparatus length does not become extremely large.
[0045] (iii) With respect to the cost, assembly and the like, first, the cooler 15 has a
simple box structure, and therefore manufacture of the cooler 15 is simple and the
manufacturing cost can be reduced. In the conventional jacket structure, it is necessary
to manufacture a casing by a troublesome molding method such as molding using a core.
[0046] Second, assembling and detaching of the cooler 15 are easily performed. Specifically,
in a state where the motor shaft 5 passes through the center hole 17 of the cooler
15, the outer peripheral portion (ring member 19) of the cooler 15, the motor 1, and
the speed reducer unit 2 are connected with the connecting bolts 7, thereby completing
the mounting of the cooler 15. On the other hand, the cooler 15 can be detached from
the motor 1 and the speed reducer unit 2 by loosening the connecting bolts 7. Particularly,
the cooler 15 can be mounted by using the motor 1 and the speed reducer unit 2 connectable
with the connecting bolts 7, without adding special configurations to the motor 1
and the speed reducer unit 2.
[0047] Third, a part of the center hole 17 can be used as the communication path 18. Therefore,
a configuration of the cooler 15 can be simplified as compared with a case where the
communication path 18 is provided at a place different from the center hole 17. Thus,
the cost can be further reduced.
[0048] Fourth, a configuration of injection and discharge of the cooling medium in the cooler
15 is simple. Specifically, in the embodiment, the inlet 20 and the outlet 21 of the
cooling medium for the coolant path 16 are provided on the outer peripheral portion
(ring member 19) of the cooler 15, and therefore the cooling medium can be directly
injected into the cooler 15 from the outside, and directly discharged from the cooler
15 to the outside. Therefore, a configuration of injection and discharge of the cooling
medium can be simplified, for example, as compared with a case where the inlet and
the outlet of the coolant are provided on the casing 4 of the speed reducer unit 2
and are brought in communication with the cooler 15. Therefore, the assembly, the
processing, and the cost become further advantageous.
[0049] (iv) It is possible to easily switch between the connection state, in which the motor
1, the speed reducer unit 2, and the cooler 15 are connected as shown in Fig. 1, and
the detaching state, in which the motor 1 and the speed reducer unit 2 are connected
while the cooler 15 is detached as shown in Fig. 4. Specifically, the motor 1 and
the speed reducer unit 2 are detachably connected with the connecting bolts 7. Moreover,
the cooler 15 has the bolt through holes 22 detachably connected to the motor 1 and
the speed reducer unit 2 with the connecting bolts 7. Therefore, the connection state
and the detaching state can be easily switched by screw engagement operation of the
connecting bolts 7.
[0050] In a case where cooling of the lubricating oil O is not needed, such as a case for
cold regions, it is possible to eliminate waste of equipment by switching to a specification
where the cooler 15 is not provided (detaching state).
[0051] In order to achieve both of the case where the cooler 15 is provided and the case
where the cooler 15 is not provided, the following three elements are needed.
[0052] First, a length of the motor shaft 5 is set to the size obtained by adding a length
corresponding to a thickness of the cooler 15 to an original length necessary for
mounting the sun gear S1 of the first-stage planetary gear mechanism 12.
[0053] Second, an axial mounting position of the sun gear S1 with respect to the motor shaft
5 is changeable.
[0054] Third, in the state where the cooler 15 is not provided, a surplus portion (lower
end), located below the sun gear S1 of the first-stage planetary gear mechanism 12,
of the motor shaft 5 is inserted into the central portion of the sun gear S2 of the
second-stage planetary gear mechanism 13.
Second Embodiment (see Fig. 5)
[0055] In the following embodiment, the same portions as the first embodiment are denoted
by the same reference numerals, and only difference from the first embodiment will
be described.
[0056] According to a second embodiment, a speed reducer unit 2 has a plurality of stages
of planetary gear mechanisms (two-stage planetary gear mechanism in an example in
the drawing, and hereinafter described as a case of the two-stage planetary gear mechanism)
12 and 13 arranged in a row in an apparatus-axis direction. Then, a cooler 15 is provided
between the adjacent both planetary gear mechanisms 12 and 13.
[0057] A configuration of the cooler 15 is the same as that of the first embodiment.
[0058] A casing 4 (including a ring gear R) of the speed reducer unit 2 is divided into
an upper casing 4a and a lower casing 4b.
[0059] Similarly to the first embodiment, the cooler 15 is mounted to the casing 4 with
connecting bolts 7 in a state of being held between the upper casing 4a and the lower
casing 4b.
[0060] According to this second embodiment, the cooler 15 is more deeply immersed in lubricating
oil O. Therefore, even in a case where an oil level of the lubricating oil O is lowered
to some extent, heat exchange action is reliably performed on both of the upper and
lower sides of the cooler 15. Thus, a cooling effect is further enhanced.
Third Embodiment (see Figs. 6 and 7)
[0061] A third embodiment and a fourth embodiment described later are similar to the second
embodiment in that a cooler is provided between adjacent planetary gear mechanisms.
However, the both third and fourth embodiments are also applicable to a configuration
in which the cooler is provided between a motor 1 and a speed reducer unit 2, similarly
to the first embodiment.
[0062] As shown in Fig. 6 and Fig. 7, a cooler 25 according to the third embodiment is provided
between a first-stage planetary gear mechanism 12 and a second planetary gear mechanism13.
The cooler 25 includes a ring-shaped flange 23, and at least one pipe bodies 24 (case
of two pipe bodies shown in the drawings will be described) provided on an inner peripheral
side of the flange 23.
[0063] As shown in Fig. 7, the flange 23 has a pair of halved ring pieces 23a and 23b. The
respective ring pieces 23a and 23b each have a shape formed by halving a block body,
which has a constant thickness in a vertical direction and is formed in a doughnut-shape
in plan view, by a plane surface including an axis line Ce. That is, the block body
having the constant thickness in the vertical direction and formed in the doughnut-shape
in plan view is configured by joining the respective ring pieces 23a and 23b together.
The pipe bodies 24 are mounted between these both ring pieces 23a and 23b so as to
become bridges between the ring pieces 23a and 23b.
[0064] Furthermore, the flange 23 is provided with inlets 26 and outlets 27 leading to the
inside of the pipe bodies 24. The inlets 26 are connected to coolant supply pipes
28. Furthermore, the outlets 27 are connected to coolant discharge pipes 29.
[0065] The pipe bodies 24 each have a coolant path therein. Furthermore, an outer periphery
of each of the both pipe bodies 24 is provided with a plurality of fins 31 over the
whole length of each of the pipings 24.
[0066] Clearance gaps 30 (denoted with a reference numeral only in Fig. 7) formed between
the pipe body 24 and the pipe body 24 and between an inner peripheral surface of the
flange 23 and the pipe bodies 24 configure communication paths allowing lubricating
oil O to circulate between spaces on both sides in an apparatus-axis direction of
the cooler 25.
[0067] According to this third embodiment, in addition to basic effects similar to those
of the second embodiment, the weight and the cost of the cooler 25 are reduced.
[0068] Moreover, heat exchange of the lubricating oil O is performed by utilizing the whole
peripheries of the pipe bodies 24 and the pluralities of fins 31, thereby achieving
excellent cooling efficiency.
Fourth Embodiment (see Figs. 8 and 9)
[0069] In a fourth embodiment, an air-cooled cooler 32 formed in a spool shape is employed.
[0070] This cooler 32 includes a short cylindrical trunk portion 33, a pair of upper and
lower collar portions 34 provided to protrude from respective sides in an apparatus-axis
direction of this trunk portion 33 toward an outer periphery side, and a plurality
of tubes 36 (four in the present embodiment: two are shown in Fig. 9) provided between
the upper and lower jaw portions 34. In a state where the cooler 32 is mounted between
both planetary gear mechanisms 12 and 13, a concave portion 35 which serves as a coolant
path taking therein the air as a cooling medium is formed around the trunk portion
33 between the pair of collar portions 34. Each of the jaw portions 34 is formed with
a plurality of communication holes 34a (four in the present embodiment) that communicates
between upper and lower spaces of each of the jaw portions 34 so as to allow communication
with the inside of the tubes 36 described later. The respective communication holes
34a are provided at a plurality of places in a circumferential direction of the trunk
portion 33.
[0071] The plurality of tubes 36 is provided at a plurality of places in the circumferential
direction of the trunk portion 33 to correspond to the aforementioned respective communication
holes 34a. The respective tubes 36 each configure a communication path communicating
between the spaces on the both sides of the cooler 32 and allowing lubricating oil
O to circulate.
[0072] Moreover, a plurality of fins 37 is provided on an outer periphery of each tube 36.
[0073] The fins 37 are denoted by a reference numeral only in Fig. 9.
[0074] According to this fourth embodiment, a cooling medium, and a configuration for injection
and discharge of the cooling medium are not needed unlike a liquid-cooled cooler.
Therefore, the cooler 32 can be simplified, thereby enabling reduction in cost and
weight.
[0075] Moreover, a surface area contributing to heat exchange can be increased by the spool
shape in which the concave portion 35 is formed between the pair of collar portions
34. Therefore, a high cooling effect can be obtained.
[0076] Additionally, the spaces on the both sides in the apparatus-axis direction of the
cooler 32 are in communication with each other by the plurality of tubes 36 passing
in the concave portion 35. Therefore, the lubricating oil O can move in and out between
the spaces on the both upper and lower sides of the cooler 32 through the tubes 36,
and is cooled by losing heat to the air inside the concave portion 35 when passing
through the concave portion 35. Particularly, according to the embodiment, the plurality
of fins 37 is provided on the outer periphery of each tube 36, and hence the heat
exchange action is intensified and a cooling effect can be further enhanced.
[0077] The above-mentioned specific embodiments mainly include the inventions having the
following configurations.
[0078] Specifically, the present invention provides a drive apparatus for a construction
machine that includes a hydraulic or electric motor having a motor shaft and serving
as a drive source, a speed reducer unit having a speed reducer output shaft for receiving
rotation force from the motor shaft and transmitting the rotation force to the driven
portion, and a casing having lubricating oil injected therein, and transmitting the
rotation force of the motor to the driven portion while reducing speed of the rotation
force, and a cooler formed with a coolant path through which liquid or gas for cooling
the lubricating oil passes as a cooling medium, wherein the motor and the speed reducer
unit are provided in a row in an apparatus-axis direction such that the motor shaft
and the speed reducer output shaft are arranged along a same line, and the cooler
is provided in a row with the speed reducer unit in the apparatus-axis direction in
a state where at least a part of the cooler is immersed in the lubricating oil, so
as to enable heat exchange with the lubricating oil.
[0079] According to the present invention, in the state where at least the part of the cooler
is immersed in the lubricating oil so as to enable the heat exchange with the lubricating
oil, this cooler is provided in a row with the speed reducer unit in the apparatus-axis
direction. Therefore, a surface area contributing to the heat exchange can be increased
as compared with a conventional jacket structure in which the heat exchange with the
lubricating oil is performed only from an outer periphery side by a coolant path provided
on a peripheral wall of a casing. Thus, a cooling effect with respect to the lubricating
oil can be improved.
[0080] Furthermore, according to the present invention, no coolant path is formed on the
peripheral wall of the casing, and hence a diameter of the drive apparatus can be
reduced and a space occupied by the drive apparatus as viewed from an axial direction
can be reduced as compared with the conventional jacket structure. Thus, the degree
of freedom at the time of laying out apparatuses around the drive apparatus is improved,
and a conventional problem that tightening operation or loosening operation of mounting
bolts with respect to the frame of the construction machine (upper frame in a case
of a shovel) is troublesome because the cooler protrudes to the outer periphery is
resolved.
[0081] Furthermore, as compared with a case of forming the coolant path so as to have the
size in a range of a thickness of the casing, a particular molding method such as
molding using a core for the coolant path is not needed. Thus, the cooler is easily
manufactured, and the cost can be reduced.
[0082] The "drive axis direction" means a direction parallel to the same line on which the
motor shaft and the speed reducer output shaft are arranged.
[0083] Furthermore, the "arranged in a row the speed reducer unit in the apparatus-axis
direction" includes not only the meaning that the whole of the speed reducer unit
is arranged on one side in the apparatus-axis direction with respect to the cooler,
but also the meaning that in a case where the speed reducer unit is divided in the
apparatus-axis direction, the cooler is arranged between the divided respective portions,
and the meaning that the cooler is housed in the speed reducer unit.
[0084] In the drive apparatus, the motor, the speed reducer unit, and the cooler are preferably
mounted to a frame provided in the construction machine, in a vertical arrangement
where the motor, the speed reducer unit, and the cooler are arranged in a row in a
vertical direction such that the aforementioned motor is located at a top.
[0085] According to this aspect, the motor, the speed reducer unit and the cooler are arranged
in the vertical arrangement in the vertical direction, so that a planar space occupied
by the drive apparatus can be further reduced. Therefore, particularly, in a situation
where there is not an enough space in a diameter direction while there is an enough
constant space in the vertical direction as in a case where the slewing drive apparatus
is provided in the shovel, the degree of freedom of layout of apparatuses is improved.
[0086] In the drive apparatus, the speed reducer unit preferably has at least a single-stage
planetary gear mechanism.
[0087] According to this aspect, the planetary gear mechanism which is compact in an axial
direction is used. Therefore, even when the cooler is provided on an intermediate
portion in the apparatus-axis direction, the whole length does not become extremely
large.
[0088] In the drive apparatus, the cooler is preferably provided in a state where both side
surfaces of the cooler in the apparatus-axis direction are in contact with the lubricating
oil so as to enable heat exchange with the lubricating oil.
[0089] According to this aspect, the surface area contributing to the heat exchange can
be further increased, and hence a cooling effect can be further enhanced.
[0090] In the drive apparatus, the cooler preferably has a connecting portion which is detachably
connected to at least one of the motor and the speed reducer unit, such that switching
between a connection state, in which the motor, the speed reducer unit, and the cooler
are connected one another, and a detaching state, in which the motor and the speed
reducer unit are connected each other while the cooler is detached therefrom, is enabled.
[0091] According to this aspect, the cooler has the connecting portion which is connectable
to at least one of the motor and the speed reducer unit. Thus, in a case where cooling
is not needed, such as a case for cold regions, it is possible to switch to a specification
where the cooler is not provided, and hence it is possible to eliminate waste of equipment.
[0092] In the drive apparatus, the cooler is preferably provided between the motor and the
speed reducer unit.
[0093] According to this aspect, the motor and the speed reducer unit which are detachably
connected with bolts are used, so that the cooler can be easily mounted by holding
the cooler between the bolt and the motor and bolting the both.
[0094] In this case, in order to add the cooler, a length of the bolt is simply increased.
Thus, particular processing for the motor and the speed reducer unit is not needed,
and hence a cheap cost is attained.
[0095] In the drive apparatus, the speed reducer unit preferably has a plurality of stages
of speed reduction mechanisms arranged in a row in the apparatus-axis direction, and
the cooler is preferably provided between the adjacent speed reduction mechanisms.
[0096] According to this aspect, the cooler is in contact with the lubricating oil on the
both sides in the apparatus-axis direction. Therefore, equal heat exchange action
is performed on the both sides in the apparatus-axis direction of the cooler, thereby
further enhancing a cooling effect.
[0097] In the drive apparatus, the cooler is preferably provided with a communication path
communicating between spaces on both sides of the cooler in the apparatus-axis direction
such that the lubricating oil is allowed to circulate.
[0098] According to this aspect, particularly, in a case where the cooler (coolant path)
is placed in contact with the lubricating oil on the both sides in the drive axial
direction, it is possible to spread the lubricating oil between the spaces on the
both sides in the apparatus-axis direction of the cooler. Therefore, lubrication of
the speed reducer unit can be inhibited from being blocked by the cooler, and the
cooling effect by the cooler can be further enhanced.
[0099] In the drive apparatus, an inlet and an outlet of the cooling medium for the coolant
path are preferably provided on an outer peripheral portion of the cooler.
[0100] According to this aspect, the cooling medium can be directly taken in and out with
respect to the cooler from the outside. Therefore, a configuration of injection and
discharge of the cooling medium can be simplified, for example, as compared with a
case where the inlet and the outlet of the coolant are provided on the casing of the
speed reducer unit and are brought in communication with the cooler. Therefore, the
assembly, the processing, and the cost become further advantageous.
[0101] In the drive apparatus, the cooler is preferably a box body having the coolant path
therein and flattened in the apparatus-axis direction.
[0102] According to this aspect, the cooler can be formed by the box body. Therefore, assembly
of the cooler itself is simplified, and a cheap cost is attained.
[0103] In the drive apparatus, the flattened box body is formed with a communication hole
communicating between spaces on the both sides of the cooler in the apparatus-axis
direction such that the lubricating oil is allowed to circulate, in a state of being
mounted to the construction machine.
[0104] According to this aspect, it is possible to spread the lubricating oil between the
spaces on the both sides in the apparatus-axis direction of the cooler through the
communication hole. Therefore, lubrication of the speed reducer unit can be inhibited
from being blocked, and the cooling effect by the cooler can be further enhanced.
[0105] Furthermore, the communication hole is used also as a hole receiving the motor shaft
or the speed reducer output shaft therethrough, so that the configuration is simplified
as compared with a case where holes receiving the respective shafts therethrough and
the communication hole are provided at different places. Therefore, the manufacturing
cost of the cooler can be further reduced.
[0106] In the drive apparatus, the cooler preferably includes a ring-shaped flange, and
at least one pipe body provided on an inner peripheral side of the flange and having
a coolant path therein, and a clearance gap between the flange and the at least one
pipe body or a clearance gap between the adjacent pipe bodies preferably communicates
between the spaces on the both sides of the cooler in the apparatus-axis direction
such that the lubricating oil is allowed to circulate, in a state of being mounted
to the construction machine.
[0107] According to this aspect, the cooler can be formed by the ring-shaped flange and
at least one pipe body. Therefore, the cheap cooler with a light weigh can be provided.
[0108] Moreover, the whole periphery of the outer peripheral surface of the pipe body located
inside the flange can be used for heat exchange with the lubricating oil, and hence
cooling efficiency is excellent.
[0109] In the drive apparatus, the cooler preferably includes a short cylindrical trunk
portion, and a pair of collar portions protruding from respective ends of the trunk
portion in the apparatus-axis direction toward an outer peripheral side, and a concave
portion which serves as a coolant path taking therein air as the cooling medium is
preferably formed between the trunk portion and the pair of collar portions.
[0110] As in this aspect, by employing the air-cooled cooler, the configuration of the cooler
can be simplified as compared with a liquid-cooled cooler. Thus, reduction in cost
and weight can be attained.
[0111] Moreover, the surface area contributing to heat exchange can be increased by the
shape in which the concave portion is formed between the pair of collar portions.
Therefore, a high cooling effect can be obtained.
[0112] In the drive apparatus, the cooler preferably further includes a tube provided between
the pair of collar portions, and communicating between the spaces on the both sides
of the cooler in the apparatus-axis direction such that the lubricating oil is allowed
to circulate.
[0113] According to this aspect, the spaces on the both sides in the apparatus-axis direction
of the cooler are in communication with each other with the tube. Therefore, the lubricating
oil circulates through the tube, so that the cooling effect can be further enhanced.
[0114] In the drive apparatus, a plurality of fins is preferably provided on an outer surface
of the cooler.
[0115] According to this aspect, the cooling efficiency of the cooler can be enhanced by
the fins.
[0116] Furthermore, the present invention provides a construction machine including the
drive apparatus, and a driven portion driven by force transmitted through the speed
reducer unit.
[0117] The construction machine preferably further includes a frame, to which the motor,
the speed reducer unit, and the cooler are able to be mounted in a vertical arrangement
where the motor, the speed reducer unit, and the cooler are arranged in a row in a
vertical direction such that the motor is located at a top.
[0118] According to this aspect, the construction machine further includes the frame, on
which the motor, the speed reducer unit, and the cooler are able to be mounted in
the vertical arrangement in the vertical direction. Thus, the planar space occupied
by the drive apparatus can be reduced. Therefore, particularly, in a situation where
there is not an enough space in a diameter direction while there is an enough constant
space in the vertical direction as in a case where the slewing drive apparatus is
provided in the shovel, the degree of freedom of layout of apparatuses is improved.
Industrial Applicability
[0119] According to the present invention, a cooling effect of lubricating oil is enhanced
and a manufacturing cost can be reduced while the size is small in a diameter direction.
Explanation of Reference Numerals
[0120]
- Ce
- Axis line
- O
- Lubricating oil
- P1, P2
- Planetary gear
- R
- Ring gear
- S1, S2
- Sun gear
- 1
- Motor
- 2
- Speed reducer unit
- 3
- Motor housing
- 3a
- Flange
- 4
- Casing
- 5
- Motor shaft
- 6
- Speed reducer output shaft
- 7
- Connecting bolt
- 10
- Upper frame
- 11
- Mounting bolt
- 12, 13
- Planetary gear mechanism
- 14
- Pinion
- 15
- Cooler
- 16
- Coolant path
- 17
- Center hole
- 18
- Communication path
- 20
- Inlet
- 21
- Outlet
- 23
- Ring-shaped flange
- 24
- Pipe body
- 25
- Cooler
- 26
- Inlet
- 27
- Outlet
- 28
- Coolant supply pipe
- 29
- Coolant discharge pipe
- 30
- Clearance gap
- 31
- Fin
- 32
- Cooler
- 33
- Trunk portion
- 34
- Collar portion
- 35
- Concave portion
- 36
- Tube
- 37
- Fin
1. A drive apparatus for a construction machine, comprising:
a hydraulic or electric motor having a motor shaft and serving as a drive source;
a speed reducer unit having a speed reducer output shaft for receiving rotation force
from the motor shaft and transmitting the rotation force to a driven portion, and
a casing having lubricating oil injected therein, the speed reducer unit transmitting
the rotation force of the motor to the driven portion while reducing speed of the
rotation force; and
a cooler formed with a coolant path through which liquid or gas for cooling the lubricating
oil passes as a cooling medium, wherein
the motor and the speed reducer unit are provided in a row in an apparatus-axis direction
such that the motor shaft and the speed reducer output shaft are arranged along a
same line, and
the cooler is provided in a row with the speed reducer unit in the apparatus-axis
direction in a state where at least a part of the cooler is immersed in the lubricating
oil so as to enable heat exchange with the lubricating oil.
2. The drive apparatus for a construction machine according to claim 1, wherein the motor,
the speed reducer unit, and the cooler are mounted to a frame provided in the construction
machine, in a vertical arrangement where the motor, the speed reducer unit, and the
cooler are arranged in a row in a vertical direction such that the motor is located
at a top.
3. The drive apparatus for a construction machine according to claim 1 or 2, wherein
the speed reducer unit has at least a single-stage planetary gear mechanism.
4. The drive apparatus for a construction machine according to any one of claims 1 to
3, wherein
the cooler is provided in a state where both side surfaces of the cooler in the apparatus-axis
direction are in contact with the lubricating oil so as to enable heat exchange with
the lubricating oil.
5. The drive apparatus for a construction machine according to any one of claims 1 to
4, wherein
the cooler has a connecting portion which is detachably connected to at least one
of the motor and the speed reducer unit, such that switching between a connection
state, in which the motor, the speed reducer unit, and the cooler are connected one
another, and a detaching state, in which the motor and the speed reducer unit are
connected each other while the cooler is detached therefrom, is enabled.
6. The drive apparatus for a construction machine according to any one of claims 1 to
5, wherein
the cooler is provided between the motor and the speed reducer unit.
7. The drive apparatus for a construction machine according to any one of claims 1 to
5, wherein
the speed reducer unit has a plurality of stages of speed reduction mechanisms arranged
in a row in the apparatus-axis direction, and
the cooler is provided between adjacent speed reduction mechanisms.
8. The drive apparatus for a construction machine according to any one of claims 1 to
7, wherein
the cooler is provided with a communication path communicating between spaces on both
sides of the cooler in the apparatus-axis direction such that the lubricating oil
is allowed to circulate.
9. The drive apparatus for a construction machine according to any one of claims 1 to
8, wherein
an inlet and an outlet of the cooling medium for the coolant path are provided on
an outer peripheral portion of the cooler.
10. The drive apparatus for a construction machine according to any one of claims 1 to
9, wherein
the cooler is a box body having the coolant path therein and flattened in the apparatus-axis
direction.
11. The drive apparatus for a construction machine according to claim 10, wherein
the flattened box body is formed with a communication hole communicating between spaces
on the both sides of the cooler in the apparatus-axis direction such that the lubricating
oil is allowed to circulate, in a state of being mounted to the construction machine.
12. The drive apparatus for a construction machine according to any one of claims 1 to
9, wherein
the cooler includes a ring-shaped flange, and at least one pipe body provided on an
inner peripheral side of the flange and having a coolant path therein, and
a clearance gap between the flange and the at least one pipe body or a clearance gap
between adjacent pipe bodies communicates between the spaces on the both sides of
the cooler in the apparatus-axis direction such that the lubricating oil is allowed
to circulate, in a state of being mounted to the construction machine.
13. The drive apparatus for a construction machine according to any one of claims 1 to
8, wherein
the cooler includes a short cylindrical trunk portion, and a pair of collar portions
protruding from respective ends of the trunk portion in the apparatus-axis direction
toward an outer peripheral side, and
a concave portion, which serves as a coolant path taking therein air as the cooling
medium, is formed between the trunk portion and the pair of collar portions.
14. The drive apparatus for a construction machine according to claim 13, wherein
the cooler further includes a tube provided between the pair of collar portions and
communicating between the spaces on the both sides of the cooler in the apparatus-axis
direction such that the lubricating oil is allowed to circulate.
15. The drive apparatus for a construction machine according to any one of claims 1 to
14, wherein
a plurality of fins is provided on an outer surface of the cooler.
16. A construction machine comprising:
the drive apparatus according to any one of claims 1 to 15; and
a driven portion driven by force transmitted through the speed reducer unit.
17. The construction machine according to claim 16, further comprising a frame to which
the motor, the speed reducer unit, and the cooler are able to be mounted in a vertical
arrangement where the motor, the speed reducer unit, and the cooler are arranged in
a row in a vertical direction such that the motor is located at a top.